Variable-speed power-transmission mechanism.



W. I TWOMBLY.

VARIABLE SPEED POWER TRANSMISSION MECHANISM.

APPLICATION .IILED APR.12, 1910.

INVENTOR: rdIrvLn Wmmblj BY 6 2 ATTORNEY 3 SHEETS-SHEET l.

Patented Sept. 17, 1912.

' Willa W. I; TWOMBLY. VARIABLE SPEED POWER TRANSMISSION MECHANISM! APPLICATION FILED APR. 12,1910.

Patented Sept. 17, 1912.

a SHEET8SHEET 2.

Q E Q INVENTOR. WiQgrd Irvingfiombly' w ATTORNEY y W. I. TWOMBLY. VARIABLE SPEED POWER TRANSMISSION MECHANISM.

1,038,689, Patented Sept .17, 1912.

3 SHEETS-SHEET 3.

APPLICATION FILED APR.12, 1910.

ITNESSES: INVE t Wilk vgl lrvmgfi inbbg ATTORNEY cation,

power transmission the selective type:i

iwiti'nnn IRVING rwomnmr,

or new some n. Y"? emits,

11w mien."

nnnrs, 1'0. TWOMBLY MOTORS oomrm, on NEW roux, mime commence OF NEW YORK. I

insaeee.

To all whom it may concern.

Be it known that I W'ILLARD L TWOM .a citizen of the United'States, residing the borough of Manhattan, in the city, county, and State of New York, have hi venteda new and useful'lmprovement in Variable-Speed Power-Transmission Mechanism, ot'which the following is a specifi- 'Th'is invention relates to variable speed mechanism, and it is the object ofthe invention. to provide a transnnssion'mechanism of this character of and reverse spec smay be obtained.

It is a further I provide a transmission mechanism that is simple, compact and cheap in construction,

bled, and will be efiici'ent in operation.

, --'In-earrying out the invention I provide a driving element having a pluralityof single v and multiple threaded worms, the pitch of ,i may mesh,.se e'cti-ve mechanism-being pro- 1 vided tothrew of the drive-sha at least one of-whic'h-worms is opposite to and a driven element having a worm Wheel connected:

the "pitch of theother worms,

thereto with which either one of the worms either one of. said worms into mesh with the worm wheel to: transmit variable forward and reverse speeds to the driven element; all of which mechanism is operatively' mounted in a suitable casing. I

' In the drawings accompanying and forming a part of is a plan View partly-in section. Fig. 3 ma drive shaft.

sit-ions of the parts when one of the worms is in mesh with the worm wheel. Fig. 6 is a view similar to Fig. "5, but illustrating the parts in the positions they assume when the worms. are thrown out of mesh with the worm wheel. Fig. 7 is a sectional end elevation taken on the line XX of Fig. '1' lookin in the direction of the arrow, the parts sing in operative position; and Fig. 8 is a similar view, but illustrates the worm Speeiflcation of letters Yatent ,Amlicafldn med Apri 12, 91.0- warm-mm.-

cable toother whereby variable forward object of the invention to (designated parts are easily assem 7 and housing for axle 'rie an eccentric disk the ends of the casing, Qonnectedto A or formed integral' this specification, Figure 1 is a side elevation, partly in section, of my improved transmission mechanism. 'Fig. 2'

vanIA Ln-srnnn nownn-fraansmssion V aaa a at1ai912.

worm wheel.

in neutral position-nut, off mesh the Similar characters of reference designate like parts throughout different views-of the "In the presentinstance I have shown the --transmissionmechanism as afplied to-"the axle of the driving wheels 0 a motor-ye .hlcle, such .as an automobile, to {form a part of the driving-mechanism thereof, although itwill be'oibvious that it" is appiipurposes for which a variable speed power transmission mechanism" "is adapted. g A primary power or drive shaft 1, neoted to any suitable source of power] (not shown) is journaled in the ends ofa casing in a generalway by A), oomprising an upper section'2 and a lower sec-- I tion 3 releasably' secured together in any suitable manner, as by--'screws 3', said lowersectionB not only serving as the bearing the driven shaft, but also in the ipresentinstance constitutes the wheel bearings for the shaft '1 compriseball bearings otf consisting of a ordinary construction each collar 4 surrounding the shaft, and a ring 5 surrounding said collar, r

race-ways being'formed in said collar and rin for balls' 6. Eachb'all bearing is car-' 7 rotatabiy mount; edin said ecoentrie disks, therewith, are gears 8 meshing with pin ions '9 fixed to {a shaft 10 journaled the lower case section 3, and provided withfa projecting portion 11' having I a helical groove or thread 12. Mounted jecting shaft portion 11 is a sleeve 13 "in-the form of a nut havinga thread correspondon said proing to, and engaging with the thread .12 in the shaft portion 11. operating lever or actuator 15 has a forked portion 16' to straddle the sleeve 13 and whereby the lever is connected to the sleeve, said. lever operable to slide the sleeve along theshaft-portion 11- 'to impart rotary motion to said shaft and described.

That portion of shaft 1 within the casing pinions 9 and to the eccentric 7, the function of which will jbehereinafter 25 v single threaded the same as different forward.

' single threaded; and

I speed.

worms. Said by a series oftie .ing movement thereona series of sage and multiple threaded worms 17,18, 19 and 20, all of said worms bein ter, and pitch" but ofifi'ei'ent' angles, and the pitch of one of which worms,as 17 for instance, is oppositeto the pitchof the other worms are adapted to mesh with and drivea worm. wheel or gear .35

fixed ona shaft 36. For illustration I have shown inthe drawings'the-drive jshaft'as provided'with four worms to transmit three speeds and one'reverse s aft, the worm 18 being the pitch or lead so ortionedthat the ratio thereof with speed to the driven relation to the pitch of the worm wheel will be'twenty to one; that is,

twenty revolutions of the drive shaft will impart one revolution to the driven shaft. The worm 19 is double threaded, and the ratio thereof to the worm wheel is'tento one and worm 20 is triple threaded, the ratio thereof to the worm wheel bein six and two-thirds to one. The pitch 0 the worm 17 ,as already stated, is opposite to the other worms, and the worm 18, to impart. to the driven shaft a slow reverse While I have shown in the present instance the wormsas comprisin a series of sleeves in juxtaposition and loo ed together rods 46 (Fig. 3), it will be readily understoodthat such worms may be '27, 27 and the cut on one sleeve, .or they may be out directl on the shaft 1 and the shaft mounted in t e casing .A for endwise movement. Furthermore, the number of worms may be increased to increase the number of forward and reverse speeds, to driven shaft.

I provide a thrust bearing ateachend of the worms on the shaft 1, comprising a pair of rings 21, 22 and interpose, between said rings a series of balls 23 and ball carrier 24.

To hold the worms in assembled position the shaft 1 I\ provide outside of the thrust bearings collars 25, mounted for transverse sliding movement on the shaft 1 by means of bushings 26, and connect said collars by means of arms27, 27 secured to a rod 28' mounted for sliding movement in the upper case section 2. The connections between the ears collars comprise a pin 29 fixed in lugs 25 on the collars and engaging in slots in the arms To retain the bushings 26 against endwise' movement I secure washnotches 33 in a ers 30 to the collars 25, as by means of screws. Pivotally secured to the rod 28 outside of the casing is an operating lever or actuator 31, provided with a releasable latch 32 to engage with any one of a series of fixed rack 34 to lock the lever in any adjusted position, the above described mechanism comprising selective of the same diame-.

'stantially as said worm 20 is in shaft pressure is the-collars 25 bein be transmitted to the Y igoaaeso ineans to adjust the worm sleeve along the drive shaft. with oppositely ears or lugs 37 to en The collars 25 areiprovided and outwardl extending go in sli eways38 in the walls'ofthe casing to'lock'the worms a inst endwise movement when in mesh withthe worm wheel 35.

r The operation of themechanism is subto bein mesh with the worm-wheel 35, rotary mo-' tion being imparted wheel the driven shaft is driven at its highfollows: Assuming the' parts' the positions. in Fig. 1, with the worm 20 at the extreme right-hand end to'said worm bythe f I shaft 1 from any suitable source; When the mesh with the worm est velocity. When the worm 18 is in mesh with the worm-wheel the driven shaft is driven at its lowest velocity,-.and an intermediate speed beingobtained by the worm 19; when the worm 17 is in mesh with the worm-wheel a slow reverse speed is imparted to the. driven shaft 36. As above stated, the worm 20 is .in mesh with the driven shaft gear 35 transmitting high forward speed to the shaft 36. Should it now be desired to reverse the motion of said applied to the afoot-piece 39 on the operating lever or actuator 15 con-, nected to the sleeve 13, forcing said sleeve to theright of Fig. 1, the engagement of the thread -'in the sleeve with the helicalthread 12 on the shaft extension llrot ating the shaft 10 and pinions 9, and thereby rot-atin the eccentrics 7 and rocking the shaft 1, li ting the worm out of mesh with the driven shaft gear, (Fig. 8,) the lugs 37 on slid upwardly in the slideways 38 forme in the lower case section 3. The worms are now slid along the shaft -1 by means of the lever 31 connected to the rod 28 and arms 27, until the worm 17 is above the worm wheel 35 when the actuator 31 is locked in such position by thev releasable latch 32 engaging with one of the notches 33 in the rack 34. Pressure is then released from the foot-piece 39 of the actuator 15, and the actuator is returned to normal position bymeans of a spring 45, the worm on the sleeve 13 in engagement with the worm on the shaft extensionv 11 rotating the shaft 10 and pinions 9 and consequently the eccentrics in a direction opposite to that when the worm 20 was thrown out of mesh with the worm wheel 35, causing the worm 17 to fall into mesh with the worm wheel 35, the lugs 37 of the right-hand collar 35 engaging in the slideways 38 at the extreme righthand end of the. casing to lock the worms against endwise movement. The parts are now in position to transmit reverse speed to extreme right-hand position as shown in to the collars 25 by the dotted lines in Fig. 2. To again transmit 'go I an axle provided withdiflerential gearing,

forward speed to-thedrive shafts the above operationsare repeated and the worms adjusted along theshaft 1 by the lever or actuator 31, until the worm which it is desired to'throw, into mesh with the wormwheel is opposite said worm-wheel when the lever 31 is lockedin .suchposi-tion by the latch '32, pressure beingthen released from the lever vand said selected worm automatically dropping into .mesh with the wormwheel, I y s I In Fig. 3 .I have illustrated theworm wheel and driven shaft as, forming apart of and used in connection with the driving wheels of a motor vehicle. The driven shaft is in two parts and held in operative relation by means of a sectional casing 41 readily sedifferential cured together and to which the worm wheel is fixed, said casing inclosing thegearingcomprising bevel gears 42, 42' connectedto the said shaft sections and pinions 43,, 43' the casing 41, this earingcompensating for anydifierence in it e rotation of the shaft sections caused by the wheels of the vehicles,

Variations may be resorted to within the scope of the invention, and portionsof the improvements may be used without others. Having thus described my 1nvention,1I claim:

, 1. A variable speed power transmission mechanism, comprislngin combination a casing; a driving shaft journaled in eccentric bearings in said casing; a. driven shaft a toothed wheel fixed to the driven shaft; a plurality of worms mounted upon the driving shaft to rotate therewith and adjustable along the same; means to adjust the-worms along the drivin' shaft to change the speed and direction 0 the driven shaft; and 'a rotatable'shaft geared to the bearings of the driving shaft whereby as said latter shaft is rotated in one direction the .worms are thrown into mesh with the toothed wheel on the driven shaft, and when rotated in a reverse direction the worms are thrown out of mesh with said wheel.

2. A variable speed power transmission mechanism, comprising in combination a casing; a driving shaft journaled in eccentric bearings in said casing; a driven shaft; a toothed wheel fixed to the driven shaft; a plurality of worms mounted upon the driving shaft to rotate therewithand adjust-able along the same; means to adjust the worms along thedriving shaft; means to impart motion to the bearings of the driving shaft whereby to throw the worms'into or out of mesh with the toothed wheel on the driven shaft; and means connected to the worms to engage with the casing when thrown into mesh with the driven shaft wheel to lockthe driving worms against endwise movement on the driving shaftQ rotatively mounted in 3. Inra variable speed power' transmis? sion mechanism, a cas ng, a drive shaft hav- ,ing an eccentrlc bearing at each-endm said casin a plurality' of single andmultiple .threa ed worms" on the "drive" the pitch" of at least one ofkwhich is I opposite to the pitch-ofthe other worms, said worms rotating-with and slidable along the drive shaft; a' collar at each end of the worms to engage in gu'ideways 1n theeasmg to'lock said worms against endwisemovement; a driven shaft; a worm wheelconnected thereto; and selective means to ad ustthe worms "along: the drive shaft and throw: either one of said worms intoworm wheel on the driven mesh with the shaft.fl-. 4, Inv a variable speed power vtrai'isi'n-ise sion mechanism,acas1ng; a. drive" shaft hay irig anieccentric hearing at each; end in'said 5 5. Ina variable speed power transmis- S1011 mechanism, a casing; a drive shaft having an eccentric bearing at each-end in said casing; a plurality of single and multiple threaded worms mounted on the drive shaft i to rotate therewith and slide therealong pitch ofat least one of which-worms 1s 'op- 3 posite to the pitch of the other 'collar at each endof the worms in guideways in the casing to worms against endwise movement; a driven shaft; a worm-wheel thereon; and means the worms; a to engage lock; said fto throw saidworms into and out of :mesh with the worm-wheel on the-driven shaft,

comprising a gear connected to each of the eccentricbearings, a shaft having a helical slotgeais, a sleeve on the pinion shaft having a thread to engagewith the helical slot in said shaft, and a pivoted operating lever or actuator connected to said sleeve.

6. In a variable speed power transmission mechanism, a casing; a drive shaft having an eccentric bearing at each end in said casing; a plurality of single and multiple threaded worms mounted on the drive shaft to rotate therewith'and slide therealong, the pitch of at least one of which worms is opposite to the pitch of the other worms;-a collar at each .endof the worms to engage in guideways in the casing to-lock said, worms against endwise movement; a

,shaft, go worms pinions on said shaft to meshwith said 5 driven shaft; a worm-wheel thereon; means theshaft having the helical to throw said worms into and out of mesh with the worm wheel, comprising a gear connected to each of the eccentric bearings, a shaft havin a helical slot therein, pmions' on said 5 aft to mesh with the eccentric bearing gears, a nut on that portion of slot, and a pivoted operating lever or actuator connected to said nut; and means to adjust the worms along the drive shaft. 1

. 7. In a variable speed power transmission mechanism, a-casing; a drive shaft having an eccentric hearing at each endin said casing; a pluralityf'of single and multiple threadedworms mounted -'-on said shaft to rotate therewith and slide along the same,

the pitch of at least one ofwhich worms is opposite to the pitch of the other worms; a

I worms against endwise movement; a driven ving collar at each end of the worms to engage in guideways in the casing to lock-said to rotate therewith and slide along the same,

the pitch of at least one of which worms is opposite to the pitch of the other worms; a collar at each end of the worms to engage in guideways in the casing to lock said worms against ndwise movement; a driven shaft; a worm-wheel connected thereto; means to throw said worms into and out of mesh with the worm-wheel, comprising a gear connected to each of the eccentric bearings, a shaft journaled in the casing, said shaft projecting from the casing and hava helical slot therein, pinions fixed 4 thereto to mesh with the eccentric bearing gears, a sleeve on the projecting portion of said shaft having a thread to engage with the helical slot, and a pivoted operatinglever or actuator connected to said sleeve; and selective means to slide the worms along the drive shaft, comprising a rod connected to the collars at the ends of the worms, and 'a pivoted operating lever or actuator connected to said rod.'

9. In a variable speed power transmission mechanism, a casing; a drive shaft having an eccentric hearing at each end in said casing, bushings in which said eccentrics are mounted; a plurality of single and multiple threaded worms of the same pitch but varying leads, and the pitch of at least one -1,ose,ese

of which worms is opposite to the pitch of the others on the drive shaft, said worms rotating with and slidable along the drive shaft; a thrust hearing at each end of the worms; acollar also at each end of the worms outside of the thrust bearin to engage in guideways in the casing to lo worms against endwise movement; a driven shaft; a worm-wheel thereon; means to throw either one ofv said worms into mesh with the worm wheel, comprising a gear connected to each of the eccentric bearing bushings; a shaft mounted in the casing and ck the having a helical slot therein; pinions on said shaft to meshwith the ears on the eccentric bearing bushings, a t readed nut on said shaft, and a pivoted operating lever or actuator connected to said nut.

v 10. In a variable speed power transmission mechanism, a casing; a drive shaft having an eccentric hearing at each end in said casing; bushings in which said eccentrics vare mounted; a plurality of single and multiple threaded worms of the same pitch but varying leads, the pitch of at least one of which worms is opposite to the pitch of the others on the drive shaft, said worms rotating with and slidable along the drive shaft; a thrust hearing at each end of the worms; a collar also at each end of the worms outside ofthe thrust hearings to en gage in guideways in the casing to lock the worms against endwise movement; a driven shaft; a worm-wheel thereon; means to throw either one of said worms into mesh 'with the wormwheel, comprising a gear connected to each bushing of the eccentric bearings, a shaft having a helical groove mounted in the casing, pinions mounted on said shaft to mesh with the gears on the bushings, a sleeve on the shaft having a worm to engage with the helical groove therein, and a lever or actuator connected to said sleeve operable to impart rotary motion to the said shaft and pinions; and means to adjust the worms along the drive shaft, comprisinga rod connected to the collars at the ends of the worms, anda pivoted operating lever or actuator connected to said rod.

11. A variable speed power transmission mechanism, comprlsing in combination a casing; a drive shaft; eccentric hearings in the casing in which the drive shaft is journaled; a series of worms mounted on said [shaft to rotate therewith and adjustable along the same; a driven shaft; a toothed wheel fixed to said shaft with which either Zone of the drive worms are adapted to mesh; gears connected to the eccentric bearings; a shaft journaled in the casing pari allel with the drive shaft; pinions on said gshaft to mesh with the bearing gears; and Qmeans to impart rotary motion to the pinion shaft whereby to rotate the eccentric bearings and throw the drive worms into or out of mesh with the driven shaftwheel.

12. A variable speed power transmission mechanism, comprising in combination a casing; a drive shaft; eccentric bearings in said casing in which the drive shaft is journaled; aseries of worms mounted on-said shaft to rotate therewith and adjustable along the same; a driven shaft; a toothed wheel fixed to said shaft with which either one of the drive worms are adapted to mesh; gears connected to the eccentric bearings; a shaft journaled in the casing parallel with the drive shaft; pinions on said shaft to mesh with the bearing gears; means to impart motion to the pinion shaft whereby to rotate the eccentric bearings and throw 7 the drive worms into or out of mesh with the driven shaft wheel; and means connected to the drive worms adapted to engage with the casing to prevent axial movement of said worms on the shaft when in mesh with the driven shaft wheel.

13. A power transmission mechanism, comprising a driving shaft; eccentric bearings in which said shaft is journaled; a worm on said shaft; a driven shaft; a toothed wheel fixed to said latter shaft;

and means to rotate the eccentric bearings to throw the worm into or out of mesh with' the driven shaft wheel, comprising a rotatable shaft geared to the eccentric bearings,

and means to rotate said latter shaft.

14. In a variable speed power transmission mechanism, a caslng; a drive shaft;

of which worms is opposite to the pitch of the other worms; selective means to adjust the worms along the drive shaft; a driven shaft; a toothed wheel on said shaft; means to throw either one of said worms into or out. of mesh with the toothed wheel on the driven shaft; and means connected to the worms adapted to engage with the casing when the worms are thrown into mesh with the toothed wheel on the driven shaft to lock said worms against axial movement.

" WILLARD IRVING TWOMBLY.

Witnesses:

I PAULA PHILIPP,

JOHN O. SEIFERT. 

